Question: Simplify the following expression: $k = \dfrac{6zy + 6xy}{zy} - \dfrac{2zy + 2y^2}{zy}$ You can assume $x,y,z \neq 0$.
Explanation: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{6zy + 6xy - (2zy + 2y^2)}{zy}$ $k = \dfrac{4zy + 6xy - 2y^2}{zy}$ The numerator and denominator have a common factor of $y$, so we can simplify $k = \dfrac{4z + 6x - 2y}{z}$